A projectile is thrown with velocity $v$ making an angle $ heta$ with the horizontal. It just crosses the tops of two poles, each of height $h$, after 1s and 3s respectively. The time of flight of the projectile is

Question

A projectile is thrown with velocity $v$ making an angle $	heta$ with the horizontal. It just crosses the tops of two poles, each of height $h$, after 1s and 3s respectively. The time of flight of the projectile is

Dr. Abubacker · Accepted Answer

(c) $h = v\sin	heta t - \frac{1}{2}gt^{2}$
or $\frac{1}{2}gt^{2} - v\sin	heta t + h = 0$
$t_{1} + t_{2} = - \frac{- v\sin	heta}{\frac{1}{2}\ g}\ \ or\ \ t_{1} + t_{2} = \frac{2v\sin	heta}{g} = T$
or $T = (1 + 3)s = 4s$

Q. A projectile is thrown with velocity $v$ making an angle $\theta$ with the horizontal. It just crosses the tops of two poles, each of height $h$, after 1s and 3s respectively. The time of flight of the projectile is

Explanation

Reviewed by Dr. Abubacker

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